\Header{clogit}{Conditional logistic regression}
\keyword{survival}{clogit}
\keyword{models}{clogit}
\begin{Description}\relax
Estimates a logistic regression model by maximising the conditional
likelihood. Uses a model formula of the form
\code{case.status\textasciitilde{}exposure+strata(matched.set)}.
The default is to use the exact conditional likelihood, a commonly
used approximate conditional likelihood is provided for compatibility
with older software.\end{Description}
\begin{Usage}
\begin{verbatim}
clogit(formula, data, method=c("exact", "approximate"), na.action=getOption("na.action"), subset=NULL,control=coxph.control())
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{formula}] Model formula
\item[\code{data}] data frame 
\item[\code{method}] correct or approximate conditonal likelihood?
\item[\code{na.action}] missing value handling
\item[\code{subset}] subset of records to use 
\item[\code{control}] control values
\end{ldescription}
\end{Arguments}
\begin{Value}
An object of class \code{"clogit"}, which is a wrapper for a
\code{"coxph"} object.\end{Value}
\begin{Author}\relax
Thomas Lumley\end{Author}
\begin{SeeAlso}\relax
\code{\Link{strata}},\code{\Link{coxph}},\code{\Link{glm}}\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
data(infert)
clogit(case~spontaneous+induced+strata(stratum),data=infert)
\end{ExampleCode}
\end{Examples}

